Field of the Invention
The present invention relates to a CPU (central processing unit) control system for use in a virtual computer system operated by a control program capable of running a plurality of virtual computers in an actual computer provided with a plurality of CPUs, and more specifically to a CPU control system for use in a virtual computer system for running a plurality of virtual computers by allocating them CPU resources according to a desired assignment.
One of the most utilized computer technologies is a virtual computer system capable of running a plurality of virtual computers (hereinafter referred to as "guest VMs") in an actual computer using a control program CP named "a virtual computer monitor program (VM monitor)", and also capable of operating each of the guest VMs with an operating system OS.
With such a virtual computer system, a plurality of guest VMs can be operated by a plurality of CPUs by determining the assignment (ratio) of CPU resources to each of the guest VMs so as to effectively utilize the capabilities of the CPUs by the guest VMs and sequentially run the guest VMs according to assignment ratios. The guest VMs are allowed to run in high-to-low order of assignment ratio.
However, when the resources are not equally assigned to the guest VMs, those assigned a smaller amount of the CPU resources are operated more frequently as the running operation is repeatedly performed. As a result, the CPU resources are not assigned as desired, and should be optimally adjusted.